Jungle Rangers: The Quest Begins (PC/Mac Game). From the MobyGames description:
The evil Dr Bearhead, with the help of his army of Robogophers, has been deforesting a mystical island which is now in a state of peril. To help stop this menace, the player has been offered the chance to become a Jungle Ranger, starting as a junior cadet, under the supervision of the wise Eldaran.
The player will explore three unique parts of the island — Arboria, Big Rock, and Dr Bearhead's Factory — that each contains three brain training minigames based around the same principles:
Span Tasks, claimed to help improve working memory — absorbing information, storing it and manipulating it.
Continuous Performance Tasks, claimed to help sustain attention to low frequency events.
N-Back Tasks, claimed to help updating cognitive control.